Heat exchanger



NOV'. 24, 1

J. E. wATsoN ET AL HEAT EXCHANGER Filed May 26, 193D 3 Sheeis-heef 1 NOV. 24, 1931. J, E, WATSON ET AL 1,833,666

HEAT EXCHANGER Filed May 26, 1930 3 Sheets-Sheet 2 W@ '2 27 26 25 Y@ @f 2 NOV. 24, 1931. Y E WATSQN ET AL 1,833,666

HEAT EXCHANGER Filed May 26. 1950 3 Sheets-Sheet 3 2579. ijf/Y6.

i Patented Nov. 24, 1931 PATENT orifice JQHNE` WATSON AND VARNUM s. LEWIS, or NEW ROCHELLE, lNew YORK i i HEAT EXCHANGE?.

` epljii'catlbrlfrned May 26;.1930. serial No. 455,592.

This invention relates to heat exchangers andparticularly-heat exchangers of the type whichheat is Vcaused to flowv from a hotter j., fluid through' a partition or 'dividing wall "into a cooler fluidwhile saidlluids are passing through the heat exchanger. Y* 4{In' heatexchangers of this type the hotteir-or heating fluid and thev cooler fluid are passed "inV v"separate passages' or channels. and, in orderto provide the" largest amount of heat transferringsurfaces', the fluids are preferably broken up into vthin streams j in narrow alternating passages so `that each of the :heat receiving orcoolerfluid streams is ex- Y 'posed onfeach-side to a heat transmitting wall Ythat is exposed to the vhotter fluid. The passages orfchann'els through which the heating and heat` receiving 'fluids pass are thus .in lintimate contact, and 'in order to prevent a leakageand intermingling ofthe fluids, a tight or fluid proof joint must be provided for each jset of lfluid channels. Owing to 1 the; varying expansions and contractions of ,the metal of which the fluidfsepa-rating walls arelma'de, the provisionand'maintenance of fluid tight joints has heretofore presented considerable difficulty'.

-An object of ourl invention is to provide a n .Y ,heat vexchanger of Vsimple' and compactcon-v :instruction in which tight joints maybe simply and easilyformed and maintained. A further object of the invention 1s to provideY a heat exchanger of the above type in` i, which the joints or yseams inthe fluid chamvv `bers* may be'easily and readily tightened.

llVith these and other objects in view which will more fully appear-from the'following description, the invention comprises the heat `exchanger and constructions vdescribed andy `:set forth in the following specification and claims. Y

The various features of the invention are illustrated in the accompanying drawings, in ,which- "1 e F ig'. 1 is a perspective view, partly in section, of a heat exchanger embodying a preferred form of the invention.V f

5J' l'heat receivingHuid ofthe heat exchanger.

Figs. 2, 3 andfl are, respectively, a plan, side and front elevation ofa channel for the Figs. 5, 6 and 7 are, respectively, plan, side and front elevations of the *heating* Huid channel of the heat exchanger.

Fig. 8 is a detailed side elevation of a closure or joint used in the heat .receiving and heating channels of the heat exchanger.

Fig. 9 is a cross sectional view of the closure shown in Fig. S taken on line 9 9 of Fig. 8.

li"igs. lll-18, inclusive, are similar sectional views of alternative forms of/closures embodying our invention.

In the .accompanying drawings our invention is illustrated as applied to a heat exchanger for transferring `heat' from a hot gas such as an exhaust flue gas to a current of air for example, the yair to be supplied to a furnace. In this form of the invention the hot flue gases are conducted/to the lower end of the exchanger 2O by means of a flue 21, and leave the upper part of the heat exchanger through an' exhaust or outlet flue 2.2.' The cold air to be heated in the exhanger enters the upper side part of the exchanger through 'y aninlet conduitQ and the heated air is Withdrawn through an outlet conduit '24 at the lower portion of a side wall of the heat ex changer.

In the embodiment shown by Way of cx-r ample in Fig. l, the air lines 23 and 24 enter and leave the same side of the heat exhanger, the inlet flue Q3 entering throughout approximately the upper third of the area of the side of the heat exchanger and the flue 24 connecting to the lowest third of the area of the heat exchanger. Other alternatives may, however, be employed within the scope of our invention.

As the heating or flue gas enters the heat exchanger 2O it is divided into thin streams and passes through a numberL of closely` spaced, narrow, vertical passages 25 as indicated in Figs. l and 5, Which are formed between .spaced vertical plates 26 and 27 andA are closed at theirv side edges by means ofl channelv irons 28 and 29. As indicatedin Figs. 8-18, these channel irons lcomprise a web 3() that spans the distance between the plates 26 and 27 and the thickness of theplates, and flanges 31 and 32 that overlap and enclose the side edges of the plates.

After passing through the passages 25 the exhaustflue gas leaves the apparatus through the llue 22. The air entering the apparatus through the inlet conduit or flue 23 is also divided into thin streams and enters sidewise into vertical passages 33 interspersed between the flue gas passages 25. The passages 33 are closed at their upper and lower ends by` .means of channel irons 34 and 35 similar in construction and arrangement to they channel irons 28 and 29 and arranged'to overlap the plates 26 and 27 on the faces op'- posite those overlapped by the langes 31 and 32 of the channel irons 28 and 29. Each .of the plates 26 and 27 is thus connected at its top and bottom by means of channel irons extending to the neXt adjacent plate on one side, and at its side edges to the neXt adjaycent plate on the opposite side or face of the plate. The side edges of thek air passages opposite those atwhich the air enters and leaves are closed by means of a plate 36, as

lindicated in Fig. 6, and the opposite edges otV the air passages 33 between the inlet and outlet llues' 23 and 24 are closed by a narrower plate 37A so that the air entering the passages through thel iue 23 passes in a reversely ,curved path downwardly through the air passages. The heat exchanger is enclosed in a framework comprising an upper angle iron rectangular frame 38, and a similar lower or bottom frame 39 to which theliues 22 and 21 are -respectively connected, and of vertical Vposts 40 connecting the frames 38 and 39.

The lues 23 and 24 may vbe attached to the side edges of the upper and lower tramesl 38 and 39 and the posts 40 and to cross `bars 41. Y

It will be evident. also that the channel irons 34and 35 that enclose the air passages at their upper and lower ends serve to separate the air passages from the heating gas passages, and that the channel irons 28 and 29 that serve to enclose and form the heating gas channels also serve to separate them from the air inlet and outlet ducts or flues.

VThe joints Aformed between the overlapping channel ilanges 31 and 32 and the plates 26 and 27 must be made air or lluid tight kin orderto prevent the mixing or commingling of the heating gas or lluid with the heat receiving gas or fluid. lnasmuch as 'the :plates 26 andv 27 and other parts of the heat exchanger are subjected to varying temperaturesand degrees of heat as the apparatus is put into use, thejoints between the channel irons and the plates must be tight at temperatures and 'variations in temperature met within common practice. f

In our present invention this isY accomplished by providing a joint structure in which-the edge portions of the plates 26 and y27 are compressed against the Vflanges 31 and 32, and in which the pressure may be maintained at all temperature variations by maintenance or adjustment of the plates against the' flanges'31 and 32. The bars 42 and 43 are countersunk at their meeting faces at suitableintervals to receive the flaring head 44 of a stove bolt 45 which passes through Han opening in the web 30 of the channelfiron 29 and through a washer 46, and is drawn up; tightly between the channel kiron 29and the bars 42 and 43 by means of Aa nut 47. It will be obvious that` as thenut 47 is threaded tightly. onto the bolt 45 it vcompresses the washer 46tightly against the web 30, forming a tight j uint-.about the stem of they bolt 45 and also'wedges apart-the square bars 42, 43, pressing them tightly against the plates 26 and 27 and compressing the latter tightly4 againstthe flanges 31, V32 of thechannel iron 29. I

In the formshownv in Fig. 10,.a v curved plate 48 is compressed and .flattened against the plates 26 and 27 by meansA of a bolt 49 which tlattens the spreader plate 48 against a filler block 50.` 2 v The form of embodiment shownin rF ig. 11 is similar to thatqofFig. 10, except that in place cfa ller bloclr 50, a curved plate'V 51 reverse to the position of the plate 40 is employed. Y Y v i a l In the form shown in Fig. 12 a curved spreader plate 48 is used, but the filler block 50 is omitted, the edges of the plate 48 fittingV directly against the edges of Vtheplates 26 and 27 andthe web 30 of the connecting channel iron. v

The forms of embodiment shown in Figs.

13 and 14 are similar to those shown in Figs.

10 and 11, .except .that angular spreader plates 52 and 53 vare `used instead ofthe curved plates 48' and 51.

The form olf-embodiment shown in Fig. i

15 is similar to that of Fig.v 9eXcept that the spreader barsl 42 Vand 43 are spread by means of awedge-'shaped nut 54 and a bolt 55.

In the form of embodiment'shojwnin Fig. n

16, a pair of small cylindrical tubes or bars 56 and '57 are placed in the corners between the plates 26 and 27 and the channel iron 29, and are wedged into these corners by .means of a larger cylindrical pipe or bar 58 anda bolt 59 by rwhich the -pipe 58 is drawn towards the web of the channel iron. f

los

thef-fernliednrenafslowiiin Fig-517, the:

n:netting"web,L 68;.the'fweb 63- spanning' the dis'- l sion stress by meamssof a2bolt64,.there beingy a4 slight cleanancerbetween the stem' of the 1Q bolt and the nearer edges of the wal-ls 611,62',- *so that'as'tliefnut isltightiened on the bolt, the wallsli andGQSar-ef fbroedioutwardly, thereby wed'ging them more tightly against the partition walls 26 and 27 and more tightly sealving the channel irons against the partition ""twalls.

In the embodiment shown'in Fig. 18 the plates 26 and 27 are offset inwardly as at 64 and 65, the ofi'set edges being overlapped by the flanges 31 and 32 of the channel iron 29. In this way the outer surfaces of' the flanges 31 and 32 may be made even with the outer surfaces of the plates 26 and 27.

The embodiment of Fig. 18V also illustrates v.the use of a wedge 66 instead of the nut 47 for drawing the spreading bolt against the web of the channel iron. A wedging bolt having the same type of head as in Fig. 9 is shown by way of example, but it will be un- 39 Aderstood that any of the other types of wedgingdevices may be employed with the wedge 66 The nuts or tightening heads of the bolts are accessible from the exterior of the heat 3,5exchanger and, by tightening these bolts as the elements of the exchanger expand or contract, the air and gas passages may be maintained air or fluid tight. In the event that a leakage occurs, this may be readily corrected 40 by tightening the respective bolts or nutst lIn the usual arrangement of heat exchangers the heating gases enter at the bottom or lower end of the exchanger corresponding to the inlet tube 21 in the accompanying draw- 45. ings. In cases in which these flue gases are `at or near a temperature at or near which the strength of the steel isfvery low, the weight oi the upper part of' the exchanger tends to cause the lower, hotter parts of the plates to H buckle, causing deformation and warping unless a special and higher cost steel is employed. l

In our invention, however, the weight of Y the plates of the heat exchanger may be supportedgby the clamped closure channels which, in turn, may be supported by attachment of said channels to the frame 38, 39 and 40 holding the assembly, or to an intermediate plate to saidframe, thus avoiding f Yhaving the entire weight of the assembly rest upon the bottom edge of the plates,

What we claim is Y, 1. A heat exchanger having a series of spaced plates, channel irons at the top,y bottom and side edges of said plates and said channel irons having webs spanning the spaces between adjacent plates, and flanges 'enclosing' the edge portions of said plates,

each platel being connected by channel irons at the top and bottom to a plate spaced from one face and at its side edges to the plate spaced from its opposite face, and spreaders between the edge portions of said plates to compress said edge portions of said plates against the flanges of said channel irons.

2. A heat exchanger having a series of spaced plates,.c'hannel irons at the top, bottom and side edges of said plates and said channely irons having webs spanning the spaces between adjacent plates, and flanges enclosing thek edge portions of said plates, each'- plate being connected by channel irons atvthe top and bottom to a plate spaced fromr one face and at its side edges to the plate spaced from its opposite face, spreaders between the edge portions of said plates to compress said edge portions of said plates against the flanges of said channel irons, and means for expanding said spreaders against Jthe edge portions of said plates.

3. A heat exchanger element having-side plates, end retaining and closing means having flanges overlapping the outer edges of a pair of said side plates, and means for wedging said plates outwardly against said flanges.

4. A heat exchanger element having side plates, end retaining and closingmeans having flanges overlapping the outer edges of a pair of said side plates, wedging means comprising fillers'between the inner edges of said plates, and bolts extending through said. wedging andA said closing means and expanding said wedging means against said plates as said bolt is tightened, c

v5. A heat exchanger element having side plates, end retaining and closing means having flanges overlapping the outer edges of a pairl of said side plates, expanding means between the edge portions of said plates enclosed by said closing means, and bolts extending, through said expanding means and said' closing means to expand said expanding means as said bolts are tightened.

6. A heat exchanger element having side plates, channel irons spanning and overlap` ping the side edges of adjacent plates, and spreading means for compressing the edge portions ofv saidl plates against the overlappingL parts of said channel irons.

7. A heat exchanger element having side plates, channel irons spanning and overlappingthe side edges of adjacent plates, and spreading means for compressing the edge portions of said plates against the overlapping parts of said channel irons alternately at the top and bottom and at the side edges of said plates.

8. A. closure for heat exchanger elements which comprises/a pairof spaced plates, a

4f' y l Y 1,833,666 i channel iron having a web spanning the space between said plates and flanges overlapping the edge of said plates, a spreader between the edgeV portions `of eachV of saidv plates, and nieans'for expanding said spreaders.

9. A closure for heat exchanger elements which comprises a pair of spaced plates, a channel iron having a web spanning the space betweensaid plates and flanges overlapping the edge of said plates, a spreader between the edge portions of each of said plates, bolts for 'drawing said spreader towards said web and expanding it against the inner edge portions of said plates;

l0. A closure for heat exchanger` elements which comprises a pairof spaced plates, a

channel ironhaving a web spanning the space between said plates and flanges overlapping the edge of said plates, a spreader between theedge lportions of each of said plates, bolts tor` drawing said spreader towards said web and expanding it against the inner edge portions of said plates, said spreaders having a slight spreading motion. relative to the tightening motion of said bolt.

ll. A closure forheat exchanger-elements which comprises a pair of spaced plates, a

channel iron h'avinga web spanning thedistance-between said plates and having flanges overlapping the edges of said plates, a spread-l er between the overlapping edges of said plates, and a wedge bolt having an' outwardly l' wedging action against said spree-ders.

12. A closure for heat exchanger elements which comprises a pair of spaced plates, a channel iron having a web spanning the dis# tance between said plates, and flanges overlapping the edges ot said plates, a slightly curved spreader between an overlapped portion of ysaid plates, and means for flattening said curved spreader to'wedge it against said plates.` f

13. A closure for heat exchanger elements which comprises a pair otspaced plates, a channel iron having a web spanning the distance between said plates and langes over-v lapping the edges of said plates, an expansible spreader between the overlapped ledges ot said plates, and a force multiplying means to expand said spreadei's. against the over-` lapped portions of said plates.

la. A closure Jfor heat 'exchanger elements Y which comprises a pair of spaced plates, a

vchannel iron having a web spanning the distance between said plates Vand flanges overlapping the edges ofl said plates, anexpansible vspreader between the overlapped edges of said plates, and an adjustable force multi plying vmeans to expand said spreaders against the overlapped portions of said plates.

l5. A closure for heat exchanger elements which comprises a pair of'spaced plates, a

' channel iron having a web spanning the distance between said plates and -anges overlapping the edges ofsaid plates, an expansible spreader between the overlapped edges of said plates, a bolt extending through thev our hands. J OHNE. WATSON.4l

VARNUM S. LEWIS.

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